A friend of mine put a built B18C1 12.5 to 1 compression swap into his 90 CRX. He is running a PW0 chipped ecu. Ever since the swap has been completed, it has thrown a code 23 (Knock Sensor). He tried changing the knock sensor and it did not help. He also tried running the wire from the knock sensor straight to the ecu to make sure the wiring was correct. It didn't help. Anyone have any suggestions on what could be the problem?

 

detonation is a possibility. is it knocking?

 

It doesn't seem to be, but it must be since it threw the code. I personally think its the ECU, but he wanted more input from honda-tech. Any other suggestions?

 

what octane is he running? he might want to retard the timing a little. unplug the knock sensor and see if it throws the code still.